Track packing or tamping machine



March 10, 1959 Filed Oct. 13, 1954 F. PLASSER ETAL I TRACK PACKING ORTAMPING MACHINE 5 Sheets-Sheet 1 INVENTOR. Franz flasserwosef Freq/er 4TTOQNEY March 10, 1959 F. PLASSER El'AL 7 2,876,709

TRACK PACKING OR TAMPING MACHINE Filed Oct. 13, 1954 s Sheets-Shget 2III 5 lllllI/lilliliIl/II/l/Il 57 INVENTOR.

' 30 24a 24 Franz P/asser wosef T/weure'r BY 04, J04 @0411,

ATTORNEY March 10, 1959 F. PLASSER ETAL 2,876,709

TRACK PACKING OR TAMPING MACHINE 3 Sheets-Sheet 3 Filed Oct. 1s. 1954llfi ENTOR.

561V: YNFF FAWN/Q BYMMM 72 30 ,4? If 2,876,709 TRACK PACKING R TAMPINGMACHINE in: Franz Plasser and Josef Theurer, Vienna, Austria ApplicationOctober 13, 1954, Serial No. 462,086

1 claim. (Cl. 104-12) upper end, an eccenter shaft operatively connectedto the mounting device for imparting a vibratory movement to themounting device and the tamping tools linked thereto, and means forvarying the distance between the tamping tools of each pair. The ballastis packed under a tie by placing a pair of tamping tools over the tieand forcing the tamping tools together while they are simultaneouslyvibrated.

It is known to effect the spacing adjustment for each pairof'cooperating tamping tools, i. e. their approachment or closing aswell as their opening, by hydraulic means.

Known hydraulically-operated track tamping machines include a largenumber of movable parts which require-constant service, lubrication,etc., as well as a considerable number of control valves, slides, etc.in the numerous pressure fluid conduits. This makes the operation ofsuch machines excessively difiicult, breakdowns are frequent and themanufacture of the machines is very expensive. In addition, there arestructural xdifliculties in building the machines and they are extremelybulky.

It is the principal object of the present invention to provide a tracktamping machine of the above type with a considerably simplifiedoperating mechanism and greatly improved operational efiectiveness.

' It is a concomitant object of this invention to provide such a machinewith a minimum of movable parts, thus reducing operational break-downs.

It is a more specific object of the invention to provide an improvedspacing adjustment mechanism for each pair of tamping tools. Inaccordance with the invention, the spacing adjustment mechanism for eachpair of cooperating tamping tools comprises at least one cylinder closedat both ends, at least one piston in each cylinder and pressure meansfor shifting either the cylinder or the piston, the movable element(cylinder or piston) being linked with the cone sponding tamping toolintermediate its ends and the other element (cylinder or piston) beingfixedly mounted on the tamping tool carrier.

The above and other objects, features and advantages of the presentinvention will be more fully explained in the following description ofsome now preferred embodiments thereof taken in conjunction with theaccompanying drawing wherein Fig. 3 shows the operating arrangement ofthe mechanism of Fig. 2;

Fig. 4 shows the operating arrangement of another modification;

Fig. 5 is a sectional view of a detail of Fig. 4; and

Fig. 6 is a perspective view of the tamping tool carrier.

Referring now to the drawing, the same reference numerals are applied tolike parts in all figures.

Fig. 1 shows a track tamping machine incorporating a tamping toolspacing adjustment mechanism which comprises a closed cylindercooperating with each tamping tool, each cylinder being glidably mountedwith its two closed end walls on a longitudinal piston which is fixedlymounted in the vertically adjustable tamping tool carrier, the pistondividing the cylinder into two chambers. In this embodiment, hydraulicor pneumatic pressure means may be applied to the cylinder chambers, orto one chamber only. As shown, tamping tool carrier 2 is slidablysupported on posts 3 and 3' which are mounted in carriage frame 1.Eccenter shaft 4 is supported on carrier 2, the shaft axis beingparallel to ties 9 supporting track 9 upon which the carriage travels.Upon rotation, shaft 4 imparts a reciprocating motion to tamping toolmounting arms 5, the pair of tamping tools 6 and 6 being pivotablyconnected at their upper ends to the ends of mounting arms 5.Intermediate their ends, the tamping tools are linked to a pivot element7 which enables the spacing of the tamping tools to be adjusted in amanner described hereinafter. The lower ends of the tamping tools reachinto the ballast 10 at either side of ties 9. The ballast is packedunder tie 9 when the two tamping tools are moved toward each other, thusexerting pressure on the rocks and pebbles therebetween, while the toolsare simultaneously vibrated by rotation of eccenter shaft 4. The tampingtool carrier 2 is vertically movable by adjustable support means 8 (notillustrated in detail), whereby the depth of the tamping tools in theballast may be changed. When the tamping at one tie is completed, theentire carrier is raised on standards 3, 3', the carriage is moved alongtracks 9' to the next tie and the operation is repeated there.

Intermediate its ends, each tamping tool is connected to cylinder 21 bymeans of pivot 7. The cylinder is closed at both ends and is adapted toglide along fixed piston rod 22 which is mounted in the tamping toolcarrier parallel with the tracks. Piston 24, which is fixedly mountedupon or integral with the piston rod, divides the movable closedcylinder into chambers 30 and 31, pressure fluid conduit 23 opening intoouter chamber 30 while pressure fluid conduit 25 leads into chamber 31.The conduits for the pressure fluid, i. e. oil, are partiallyconstituted by bores in rod 22, as shown.

Fig. l is a side view of a ballast tamping machine ina In operation,when fluid is fed toouter cylinder chamber 30, pressure will be exertedupon the outer wall of the cylinder, thereby moving the cylinder to theright, as seen in the drawing, and imparting an outward or openingmovement to the tamping tools. Contrariwi'se, when fluid is fed tochamber 31, the tamping tools will move toward each other. The closingmovement, which should always be effected very slowly and requirescons'iderable power to assure good tamping of the ballast, is bestactuated by hydraulic means. However, for opening the tamping tools ormoving them apart from each other at the end of the tamping operation,it is advantageous to use means which work faster and thus save time.

One preferred means for moving the tamping tools apart is a helicalspring mounted in the outer cylinder chamber to return the movablecylinder (and thereby the tamping tool) to its original position whenthe hydraulic pressure in the insidechamber is released. .It

Patented Mai-.10, 1959 may be desirable to control the extent of theclosest and widest distance of the cooperating tamping tools byadjustable stops placed in the path of their movement, the adjustment ofthe stops resulting in a predetermined maximum or minimum spacing of thetools. The practically instantaneous action of the spring means willsave considerable time in opening the tamping tools because hydraulicoperation involves a relatively long time. Since the tamping tools canbe moved apart without the use of much power and should be opened asquickly as possible to assure etficient operationof the machine, the useof the hydraulic pressure for opening the tamping tools is wasteful andundesirable.

Figs. 2 and 3 illustrate the use of springs used for moving the tampingtools apart after the tamping operation. Instead of a pressure fluidconduit leading into outer cylinder chamber 30, the chamber is providedwith pressure spring 26 held between the wall of cylinder 21 and piston24. Otherwise, the spacing adjustment mechanism of Fig. 2 is the same asthat shown in Fig. 1, except for the provision of stops 27, which limitthe reciprocating movement of each tamping tool.

The operation of the apparatus shown in Fig. 2 is further illustrated inFig. 3. The pressure fluid supply to chamber 31 of each cylinder isregulated by control member 33. In the rest position, when no pressurefluid is to be fed to chamber 31, the piston in the control membet ispressed upwardly by spring 34 acting upon actuating lever 35 of thecontrol member (position shown in dotted lines). In this position of thecontrol member, pressure fluid supply from pump 12 is cut off fromconduits 25. When lever 35 is actuated against the pressure of spring34, the pressure fluid delivered from pump 12 is free to enter conduits25 through the cylinder of control member 33 (position shown in fulllines), entering chambers 31 and thus effecting the approachment of thetamping tools and tamping of the ballast therebetween. The tamping toolswill move toward each other until they hit inside stops 27. The stopsare so positioned as to avoid damageto tie 9 by the tamping tools whichare located at each side thereof to tamp the ballast under the tie. Theincreased pressure thus created in conduits 25 is released by means ofhighpressure relief valve 32 which is arranged in the return conduit25b. When lever 35 is no longer actuated, pressure fluid supply tochambers 31 is cut ofi and the tamping tools return to their original(open) position under pressure of springs 26 in cylinder chambers 30.The opening under spring pressure is, of course, effectuated muchquicker than the closing with hydraulic means.

In the rest position of control member 33, when no pressure fluid issupplied to chambers 31, the pressure fluid constantly delivered by pump12 returns to storage tank 33 by means of return conduit 25b. ifdesired, throttle or butterfly valve 29 may be arranged in returnconduit 25a to regulate the return speed of movable cylinders 21, i. e.the speed of opening the tamping tools. The return stroke of cylinders21 may also be controlled by adjustable limiting stops 27 to adapt thetarnping operation to various tie distances.

High-pressure relief valve 32 in return conduit 25b serves to adjust thedesired pressure and permits variations of the pressure duringoperation. If it is desired,

.for instance, to adjust the pressure applied to each pair of tampingtools separately, each pair of tools is provided with a separate conduitsystem having its own pressure control valve. This makes it possible,for in stance, to tamp the ballast outside the tracks more densely thantherewithin, thus preventing so-called riding of the tie,

n the other hand, equal pressure upon all pairs of tamping tools maybest be obtained by building fluid supply meters 28 into feed lines 25.This also permits regulation of theapproachment or closing speed of the4 tamping tools by varying the amount of pressure .fluid supplied to thecylinders.

Instead of using the time-saving return springs for opening the tampingtools, it is also possible to use pneumatic means for this purpose,applying hydraulic pressure for moving the tamping tools together butpneumatic pressure for moving them apart. In this instance, too,valuable operating time is saved and, in addition, it simplifies theconstruction of the machine considerably. The necessary compressed airfor the pneumatic operation will be readily available in anyconventional ballast tamping machine since it is used for otheroperational purposes, such as the vertical adjustment of the tampingtool carrier.

A practical embodiment of this variant of the invention is illustratedin Figs. 4 and 5. In this case, the return stroke of the tamping toolsis expedited by supplying compressed air to cylinder chambers 31 insteadof hydraulic fluid which is used only for closing thetamping tools.

As shown in Fig. 4, when actuating lever 36 is in position I (fulllines), control member 37 will permit by? draulic fluid, i. e. oil, tobe supplied from storage tank 38 by means of pump 12 to conduit andcylinder chambers 31. As hereinabove described, the hydraulic pressurewill close the tamping tools and effect the tamping operation. At theend of this operation, i. c. when the ballast has been .suflicientlytamped and/or the temp ing tools are limited by stops 27, the pressurefiuid delivered by pump 12 will be released by high-pressure reliefvalve 39 and enter return conduit 49 back into storage tank 38.

When hydraulic fluid is supplied to chamber .31, thus moving thecylinder to the right, as seen in the drawing, the air in cylinderchamber is displaced and flows out into the atmosphere by way of blow-0dvalve 43 because back-pressure valve 44 is provided in the pneumatic airconduit 23. The back-pressure valve prevents the air from being led backto compressor 46.

The tamping tools are moved apart after tamping by moving lever 36 intoposition 11 (indicated in dotted lines in Fig. 4). In this position ofcontrol piston 37, the hydraulic fluid will be returned without pressureto storage tank 38 by way of conduit 40. On the other hand, thecontinuously working compressor 46 will constantly supply compressed airto cylinder chamber 30 by way of pressure reducing valve 45,back-pressure valve 44, pressure-relief valve 43 and conduit 23. Thecompressed air supplied to chamber 30 will move cylinder 21 leftward (asseen in the drawing) and thus move the tamping tools apart. Thepressure-reducing valve 45 serves to adjust the air pressure so as toeliminate any vibration of cylinder 21 and may also be used to influencethe velocity of the return stroke, i. .e. the opening, of the pair oftarnping tools.

The hydraulic fluid in cylinder chamber 31 is displaced when compressedair is supplied to chamber 30, and flows back into storage tank 38 byway of conduits 25, control member 37 and conduit 46 where it combineswith the fluid coming from pump 12.

Fig. 5 shows the sealing of cylinder chambers 30 and 31 by means ofscaling rings 24a on piston 24. Any air which may have penetratedthrough the sealing ring from chamber 30, or hydraulic fluid seepingthrough from chamber 31, will reach the circumferential groove 42 ofpiston 24 which is located intermediate the sealing rings. The pressurefluid will then be conducted from groove 42 through bore 41 in thepiston rod back to storage tank 38 where-the hydraulic fluid remainsstored while the air may be permitted to dissipate.-

While some preferred embodiments of the tamping tool spacing adjustmentmechanism have been described and illustrated in detail, it will beunderstood that various "variants of the described principles may occurto the skilled in the art, particularly after they have had the benefitof the present disclosure, without departing from the spirit and scopeof the present invention as defined in the appended claim.

What is claimed is:

In a track tamping machine of the type comprising a carriage to travelon the track, a vertically movable carrier mounted on the carriage, atleast one pair of opposing tamping tools carried by the carrier toreciprocate in a direction substantially parallel to the track, andeccenter shaft means operatively connected to the upper ends of thetamping tools for imparting a vibratory movement to the tools: apressure-operated mechanism for varying the relative distance betweenthe two tamping tools of each pair of opposing tools, said mechanismincluding a piston rod fixedly mounted on the tamping tool carriersubstantially parallel to the track, two pistons fixedly arranged onsaid rod, said pistons being arranged substantially symmetrically withrespect to the center point of the piston rod, two cylinders closed atboth of their ends movably mounted on said piston rod with each of saidpistons dividing a respective one of said cylinders into an outsidechamber and an inside chamber,

pivot means connecting each tamping tool of a pair of cooperating toolsintermediate its ends to a respective one of said cylinders, andpressure means for applying pressure to each chamber of said closedcylinders, the pressure means connected to the inside chambers beinghydraulic fluid.

References Cited in the file of this patent UNITED STATES PATENTS1,980,704 Scheuchzer Nov. 13, 1934 2,052,943 Scheuchzer Sept. 1, 19362,399,505 Phillips Apr. 30, 1946 2,404,639 Lane July 23, 1946 2,550,925Weimar May 1, 1951 2,712,287 Zurrnuhle July 5, 1955 FOREIGN PATENTS182,113 Austria June 15, 1954 680,644 Great Britain Oct. 8, 1952 683,453Great Britain Nov. 26, 1952 703,011 Great Britain Jan. 27, 1954

